Cell-enclosed electric switch and disconnecting switch therefor



oct. 1o; .1933, F, H. MACNEIL 1 1,929,983

CELL ENCLOSED ELECTRIC SWITCH AND DISCONNECTING SWITCH THEREFOR .2 y/yl. f2 f jnve'zo',

F. H. MACNEIL Oct. 10, 1933.

CELL ENCLOSED ELECTRIC SWITCH AND DISCONNECTING SWITCH THEREFOR FiledJune 5, 1929 3 Sheets-Sheet 2 oct. 1o, 1933. F, H. MACNEL 1,929,983

CELL ENCLOSED ELECTRIC SWITCH AND DISCONNECTING SWITCH THEREFOR FiledJune 3, 1929 3 Sheets-Sheet 5 Patented Oct. 10, 1933 UNITED STATI-:s

CELL-ENCLOSED ELECTRIC SWITCHv AND DISCONNECTING SWITCH THEREFORFrederick H. Macneil, Boston, Mass., assigner to Condit ElectricalManufacturing Corporation, South Boston, Mass., a corporation ofMassacliusettsy Application :une s, 1929. serial No. 368,113 1s claims.(c1. fzs- 298i This invention .relates tov high potential cellenclosedelectric switches of the oil immersed type which are adapted to havetheir exposed terminals connected electrically with and discon- 5 nectedfrom fixed line terminals carried by the enclosing cell structure.

An oil immersed electric switch may be open and the contacts thereofspaced apart under the oil and yet the line conductors connectedtherewith may be charged to a dangerous potential` due to a carbonizedcondition of the oil resulting from the circuit interrupting arc drawnwithin the oil. It is necessary therefore to provide some means toisolate the switch from the line conductors. Air break disconnectingswitches of the knife blade type have been'commonly used, but theserequire so much room where the potentials are high that they becomeimpracticable. Truck type switches have also been employed havingexposed switch terminals which constitute the movable contact members ofisolating switches, the cooperating stationary contact members of whichhave been carried by the cell in position to be automatically engagedand disengaged upon movement of the switch to and from its enclosingcell. This arrangement, while compact, necessitates the removal of theswitch from its cell inorder to disconnect it from the line conductors.vIn larger sizes of switches this is in itself undesirable since theswitches are cumbersome and heavy and can be moved only with greateiort. A further diiiiculty, and one which imposes a greater limitationon this type of switch gear, is the diiilculty of moving the switch 35.into position against the friction of the coop eratingautomatically-engageable' contact members. This diiiiculty is so markedthat where 'more than two contacts are involved it is necessary toprovide some force multiplying, or racking, device to eiect theengagement of the contact members.

It is an object of this invention to provide an improved means forisolating a cell-enclosed oilimmersed switch from its circuit conductorswhich is economical of space and which is operable without moving theswitch from its circuit controlling position in the cell. l

Another object is the provision of a multi-phasey cell enclosed electricswitch and isolating means therefor having a single operating lever foreiecting the simultaneous disconnection of all of said phase units.

A further object is the provision of a disconnecting switch which in itsopen position provides an unenclosed air gap between the circuit breakerterminals and the line terminals but which in its closed position isadapted to have fully enclosed all live conducting parts thereof.

A still further object is the provision f a circuit interrupter havingterminals, and an enclosl ing cell'structure therefor having lineterminals vertically aligned with and spaced from said switch terminals,and contact members disposed between said line and switch terminals andmovable 'into and out of engagement with one of 55 said terminals andhaving a lost-motion connection with the other of said terminals.

It is a further object to provide a multi-phase cell enclosed circuitinterrupter and a plurality of vertically movable disconnecting switchestherefor having a common supporting structure, and a common operatingmeans, by which all of said disconnecting switches can be operated inunison and also by which-they canbe removed as a unit from the cell whenthe interrupter is 75 withdrawn therefrom.

A yet further object is the provision of a vertically-movabledisconnecting switch disposed between the switch and line terminals andhaving a rigid lost-motion electrical connection with one 30 of them.

A still further object of the invention is the provision of a verticallymovable intermediate disconnecting switch disposed between and adaptedto electrically connect the switch and line tersg;` minals oi a switchgear,. and means to lock said disconnecting switch against verticalmovement when the switch is closed and also to prevent opening andclosing of the switch when said disconnecting switch is disposedintermediate its fully raised and lowered positions.

A further object is generally to improve the construction andperformance of cell-enclosed switches.

Fig. 1 is an elevation of a cell-enclosed electric 95 switchembodyingthe invention, the irontA panel and connected mechanism beingbroken away.

Fig. 2 is a side elevation taken on line 2-2 of Fig. 1.

Fig. 3 is a ysectional elevation of an isolating switch of Fig. 1 in theclosed position.

Fig. 4 is an enlarged sectional detail of an intermediate' disconnectingswitch member.

Fig. 5 is a bottom plan view of Fig.4.

Fig. 6 is an enlarged perspective view showing the supporting means forthe intermediate isolating switch members and theoperating and guidingmeans therefor, parts being broken away for clearness.

Fig. 7 is a sectional detail of one of the line terminals.

Fig. 8 is a detail of the mechanism for interlocking the interrupter anddisconnecting switches showing the interrupter closed and the operatingmeans for the disconnecting switches disabled against vertical movement.

Fig. 9 is a view similar to Fig. 8, but with the interrupter locked openand thel interlocking means in position to permit the intermediatedisconnecting switches to be lowered into engagement with the switchterminals.

Fig. 10 is a detail View showing the cooperating parts of theinterlocking mechanism which pre- -vent closingl of the interrupter whenthe disconnecting switches are in an intermediate position.

The electric switch herein shown as embodying the invention includes anoil immersed circuit interrupter including the three separate phaseunits 10, 11 and 12 which are adapted to be received within a commoncell. enclosure comprising the rear wall 14, opposed side walls 16, abottom wall 18 and a top wall 20. The upper portion of saidcell isfurther v'provided with a permanent front closure 22. A horizontalpartition wall 24 in the upper portion of the cell provides an upperenclosed bus compartment 25, and a vertical partition wall 26, which isspaced from and is parallel to said rear wall 14, provides a rearconductor compartment for the outgoing lines 27.

Busses A, B, and C of a three phase power source extend transverselythrough the upper bus compartment 25 and through and beyond the sidewalls of the cell and are supported by the top wall 20 by means ofinsulating posts 28 which depend therebelow into the bus compartment ofthe cell. Insulating bushings 32 and 34 are provided for each of saidinterrupter units 10, l1 and 12 and are supported on and extend throughthe horizontal partition wall 24. Said bushings are provided with axialconducting studs 36 and 38. The upper ends of studs 36 are separatelyconnected electrically through conductors 40 with the three phase bussesA, B, and C, and the upper terminals of thestuds 38 are similarlyconnected to the outgoing line conductors 27. Contact blocks 42 arescrew-threaded to the lower ends of said studs 36 and 38 and each ofsaid blocks is provided with a pair of relatively long depending knifeblade contact members 44 which are securedremovably thereto by means ofscrews 45. Said blades 44 are adapted to provide the :fixed contactmembers of line disconnecting switches hereinafter more fully described.

The three single phase circuit interrupters l0, 1l and 12 are connectedfor conjoint operation, and in their switch open position are adapted tobe moved from the cell and for this purpose are mounted on platforms 46provided with truck wheels 48 by means of which the interrupters areadapted to be rolled on the floor 18 into and out of the cell.

Said interrupter units are identical and, as shown in Fig. 2, eachcomprises a switch frame 50 which is supported in an elevated positionabove said platform by and forms a cover for an oil receptacle 52. Saidswitch frame carries the switch operating mechanism 54 and also a pairof horizontally spaced upstanding stationary switch members 56 and 58including the insulated studs 60 which extend within the 'oil receptacle50 and terminate in the stationary contact members of the interrupter.Said stationary switch members 56 and 58, as shown in Fig. 2, areadapted to be directly beneath and axially aligned with thecorresponding bushings 32 and 34 carried by the cell when the switch isin its normal position within the cell. Said studs 60 are furtherprovided with terminal blocks 62 having upstanding ribs 64 to which theresiliently supported contact fingers 66 are secured by bolts 67. Saidthree phase units 10, 11 and 12 are provided with a common front closure68 which forms a closure for the open front of the cell when the switchis disposed therein.

According to the present invention, means are provided to make and breakthe electrical connection between the contact terminals 62 carried bythe switch and the xed contact terminals 44 carried by the cell, whilemaintaining the switch in its normal position in the cell. To. this end,a vertically movable disconnecting switch member is provided betweeneach of the switch terminals 62 and the aligned iixed line terminals 44,all of which are conjointly operable from the front of the cell toconnect and disconnect the switch from its circuit. As shown'mostclearly in Fig. 6, a horizontal supporting frame 70 is provided for saidintermediate disconnecting switch contact members which includes thespaced parallel angles 72 and 74 which extend substantially across thecell at the front and back thereof between the walls 16, and thetransverse angles 76 and 78 which are secured to the ends thereof, as bywelding, to form a rigid rectangular frame work. A channel member 79 isdisposed midway between the angles 72 and 74. Said frame 70 is adaptedto be supported in position between guiding means carried by the sidewalls 16 of the said cell. Said guiding means may comprise the channelmembers 80, only one of which is shown, having their backs secured tothe opposite side walls 16 of the cell. Rectangular guide blocks 82 aresecured to the backs of 'the transverse angles 76 and 78 midway of theframe and are adapted to be received between the .inwardly-directedparallel legs of said channel members 80 for vertical movement in thecell. Triangular web members 84 are secured to the back of said channelmember 79 and the blocks 82 by welding whereby to secure said blocksxedly to the frame.

The vertically-movable switch members of the intermediate disconnectingswitches, as shown most clearly in Figs. 4 and 5, are carried on saidframe 70 by means of supporting plates 86 which are provided withrectangular flanged openings 88 therein within which the rectangularinsulating bushings 90 are adapted tc be secured by cement. Internalconducting members 92, which conform with the rectangular axial passagesin said bushings 90 and which are of cup shape, extend through saidbushings and are provided with integral upper outstanding flanges 94which rest upon the tops thereof. Said members 92 have integral bottomportions 95 which are adapted to support the lower knife blade contacts96. Said blades 96 are adapted to be secured conductively thereto bymeans of bolts 97. Said members 92 are further provided at their upperends with three transverse ribs 98 which upstand above said anges 94 andto which the upstanding resilient contact fingers 100 are removablysecured by bolts 102. The long depending knife blade contacts 44 whichare carried xedly by the cell structure are adapted to extend downwardlyinto engagement with said contact fingers and a sub stantial distancetherebelow within the cupshaped conducting members 92 whereby, uponlowering movement of the frame from the position shown in Fig. 2 into aposition in which the lowernknife blades 96 are received andelectrically connected withv the contact fingers 66 of the switchterminals, the cooperating contacts 44 and 100 will remainin engagement.

It will be evident that with the lost-motion that is provided betweenthe upper cooperating contact members 44 and 100 of the isolating, ordisconnecting, switches, it is possible to connect and disconnect thecircuit interrupter from its circuitk without changing its position inthe cell with relation to the fixed contact members therein and, whenthe intermediate contact members are elevated into the position shown inFig. 2, a positive and visible air gap is provided between the switchterminals 62. and the line terminals 44 which will prevent charging ofthe lines 27 with a high potential.

The switch frame 70 with the movable disconnecting switch memberscarried thereby is adapted to be raised and lowered in the cell toeffect the'aforesaid engagement and disengagement between the line andthe switch terminals, and, to l this end, a pair of vertical screwthreaded shafts 103V are provided which are journalled for rotation inbearing blocks 104 carried by the channel members at the ends of theframe. Said shafts are adapted to cooperate with vertical screw threadedpassages in the blocks 82 of said frame 70 whereby to elevate the framein the cell upon the conjoint rotation of said shafts. Means areprovided to rotate said shafts 103 in unison by `a common operatinglever at the front of the cell structure. Each of said shafts 103 isaccordingly pro' vided at its upper end with a bevel gear 106"which Aisarranged to mesh with similar bevel gears 108 carried at the ends of apair of similar shafts 110 which shaftsare journalled in the bearingblocks 112 carried by vthe fixed channel member 114 which extends acrossthe cell and is welded at its ends tothe tops of the channels 80. Saidshafts 110 are provided'at their proximate ends with opposed bevel gears116 which are arranged to meshwith a common bevel gear 118 which iscar-A ried bythe operating shaft 120. Said shaft 120 extends forwardlyin the cell and terminates in a bevel gear 122, as shown in Fig. 2. Avertical shaft 124 which is journalled on' bearings 123 on the frontwall 22 of the cell is provided with bevel gears 126 and 128' at theends thereof, the gear 126'being arranged to mesh with the gear 122 ofsaid common operating shaft 120 and the gear 128 being arranged to meshwith a similar bevel gear130 carried by a short horizontal shaft 132,journalled in the bearing 123, which extends through the wall 22 andwhich is adapted to be rotated by means of a detachable crank 119, seeFig. 9, to .effect the vertical movement of the frame 70. Said shaft132, as well as the associated shafts, are located above the oilswitches and their upstanding terminals so that there is. no obstructionin the path of withdrawing movement of the switches.

' While it is desirable to provide a positive air gap in the circuitwhen the disconnecting switch is opened it is also desirable that liveconducting parts which are within the cell compartment shall be enclosedand thus protected from conducting material and which surrounds theexposed terminals of the main switch. A cooperating inverted cup-shapedmember 138 of insulating material is adapted to cooperate with a feltpacking 137 carried by the peripheral rim of said member 136 to enclosethe terminal 62 and the contact members carried thereby when thedisconnecting switch is in its lower position. Said cup-shaped member138 is secured dependingly to the bottom of said insulating bushing andis secured between said contact blades 96 and the bottom 95 of saidconducting member 92. A further insulating enclosing shell 140 isadapted to be secured between the contact terminals 42 at the lower endof said insulating bushings 32 and 34 having the depending rectangularside walls 142 which are adapted to closely surround and slide freelyover the rectangular insulating bushings 90 of said disconnectingswitches. A cooperating upstanding cupshaped member 144 is secured tosaid insulating bushing 90, as shown in Fig. 4, beneath the flange 94and is adapted to conform with the outward configuration of saidinsulating bushing 90, and to be slidably received within the side walls'of vsaid shell 140 whereby at all times to enclose v'against verticalmovement whenever the interrupter is in closed position and alsol toprevent the closing of the interrupter when the disconnectingswitchesare conditioned for vertical movement or when the disconnecting switches`are in any position other than the fully raised or lowered positionsthereof. As shown most clearly in Figs. 8 and 9, the interlocking meansincludes a bell crank 106a which is pivotally supported on a bracket108a, Fig. 2, carried by the cell structure directly beneath the bearing123 for the operating shaft 132. Said bell crank comprises a shortforwardly extending lever 109 and a longer upstanding lever 11001,having its upper Afree end reflexed laterally at 112a (Fig. 10). Saidbell crank lever l10n, has pivoted thereto at 114a a horizontalabutment' lever 116a which is supported for horizontal sliding movementby the front cell panel 22 in a position parallel to and closelyalongside the operating shaft 132 for said disconnecting switches. Saidlever 116a when in its forward position, as shown in Fig. 8, preventsthe application of the operating crank 119 for vertical movement of thedisconnecting switches.

A locking lever 118a pivoted to said cell structure at 120a'extendsrearwardly in said cell in position to cooperate with a crank arm 122awhich is operatively connected with the switch operating mechanism ofinterrupter 11. A vertical rod I124a pivoted to said locking lever at apoint 125 intermediate its ends is pivotally connected with theforwardly extended end of lever 109 of bell crank 106a. Said lockinglever is provided with a projection 12611, which is adapted vto engagethe bottom arcuate face 128a of the crank arm 122a when the switch is inclosed position, as shown inFig. 8, whereby to prevent thecunterclockwise rotation of the locking -leyer 118a. Said locking'leveris also provided witlan arcuate end face 130a which is adapted toclosely overlie a correspondingly arcuate face 132a of said crankarm122a when the interrupter is open and the locking lever is rotated ina counterclockwise direction about its pivotal support 120a, as shown inFig. 9. A projection 134a on said crank arm 122e limits the rotation ofthe locking lever 118a in a counterclockwise direction beyond that shownin Fig. 9. A vertically disposed angle'section 136a, shown most clearlyin Fig. 6, is secured to the angle 72 of frame 70 in position to receivethe reiiexed end 112a of lever 110:1. behind the forward web 14011.thereof whenever the frame 'l0 is in any position other than its fullyraised or fully lowered position, whereby to prevent the clockwiserotation of locking lever 1l8a from the position shown in Fig. 9 withthe consequent release of the crank arm 127a.

It will be evident that with the mechanism in the position shown .inFig. 8, wherein the interrupter is closed, and the lever 118a isprevented from counterclockwise rotation by the 'abutment surface 12811the lever 116a is in a'forward position and prevents application of thedisconnecting switch operating crank 119 on the shaft 132. Since theinterlocking mechanism'is biased by gravity or, if desired, by a spring,not shown, into the locking position shown in Fig. 8, the interruptercan be opened and closed if desired free from the interlockingmechanism. The position of the parts is the same when the disconnectingswitch frame 70 is in a lowered position wherein the top of the angle136a is slightlybelow the reflexed end 112a of the lever llOa.

If now the interrupter be opened, the crank arm 122a will be moved in acounterclockwise direction, and by applying the crank 119 to shaft 132,the lever 116a can be pushed inwardly by the crank whereby to rotate thelocking lever 118a in a counterclockwise direction into the positionshown in Fig. 9,' wherein the lever 110a is vertical and is free to passbehind web llllar of angle 136a, In this position of the interlockingmechanism, the disconnecting switch is in condition for verticalmovement either into or out of engagement with the switch terminals 62and the interrupter is locked against closing movement by the engagementof the cooperating faces 13011 and 132e of locking lever 118m and crankarm 122a respectively.

During the vertical movement of the disconnecting switch frame '70, thereflexed end 112a of lever llOa is disposed behind the web 140a of angle136a, which prevents the interlocking mechanism from returning to thelowered or interrupter releasing position shown in Fig. 8, regardless ofwhether the operating crank 119 is removed or not. Consequently, thebreaker is locked open until the disconnecting switch frame 70 is eitherfully lowered or fully raised, as the case may be, in which positionsthe reexed end of lever llOa will be entirely clear of angle 136a,Hence, it is impossible to cause a disastrous aro by closing theinterrupter when the disconnecting switches are in an intermediateposition.

It will be evident from Fig. 6 that upon the withdrawal of the switchfrom the cell, it is possible by the operation of the operating shaft120 to lower the disconnecting contact frame 70 below the normal switchclosed position of Fig. 2 into a still lower position wherein thescrewthreaded blocks 82 will be below and free from the screw-threadedelevating shafts 103 so that the frame 70 carrying the intermediatedisconnecting contacts can be lowered to the cell floor and withdrawnhorizontally from the cell for in'- spection and repairs.

Various modifications may be made in the construction without departingfrom the scope -of the invention.

I claim:

1. Electric switching apparatus including the combination of a maintruck type switch having switch terminals, an enclosing cell thereforhaving line terminals spaced above and vertically 4aligned with saidswitch terminals, said switch being horizontally movable into and out ofa circu't controlling position in saidI cell, a disconnecting switchcarried by said cell intermediate said vswitch and line terminals havingupper and lower contact members, said upper contact members having alost-motion electrical connection with said line terminals, and means toraise and lower said disconnecting switch in the cell, whereby to effectthe disengagement and engagement of said lower contact members and saidswitch terminals.

2. Electric switching apparatus including an enclosing cell and a switchhorizontally removably located in said cell, said cell and switch hav-.ing relatively xed vertically-aligned terminal contact members whichare vertically spaced apart, and a vertically movable switch membercarried by said cell arranged to make and break the electricalconnection between said terminal contact members and engage anddisengage the switch contact members.

3. Electric switching apparatus including the combination of a maintruck type switch having upstanding switch terminals, an enclosing cellstructure therefor having a side wall opening through which said switchis adapted to be moved into s aid cell and having depending lineterminals which are disposed above said opening and are verticallyaligned with and spaced apart from said switch terminals, a framecarried by said cell intermediate said switch and line terminals,mutually insulated conducting members carried by said frame in verticalalignment with said vterminals and having upper and lower contactmembers, said upper contact members having a lost-motion electricalconnection with said line terminals, and frame lowering and raisingmeans arranged to effect the engagement and disengagement of said lowercontact members and the cooperating switch terminals, whereby to isolatethe switch from its circuit and also to permit the switch to bewithdrawn through said opening.

4. Electric switching apparatus including an enclosing cell structurehaving depending line terrnnals in the upper portion thereof, a trucktype switch arranged to be rolled horizontally into and out of said cellstructure and having upstanding switch terminals which are verticallyaligned with said line termnals when the switch is in its terminalscarried thereby, an enclosing cell structure therefor having lineterminals aligned with and spaced above said switch terminals, a framehaving outstanding abutments on opposite sides thereof which is carriedby said cell intermediate said switch and line terminals havingconducting members extended above and below it and arranged to engageand separately connect electrically said aligned switch and lineterminals, said conducting members having a rigid lost-motion electricalconnection with one of said terminals, whereby to vpermit a relativevertical movement therebetween, means including spaced vertical shaftswhich pass through and have a screwthreaded connection with saidabutments to effect a vertical displacement of said frame, whereby todisconnect the other of said terminals and vertical guide meanscooperating with said abutments to effect a straight line verticalmovement of said frame. y

6. Electrical switching apparatus including the combination of anenclosing cell structure having a terminal supporting structure, lineterminals thereon having depending contact members, an

oil switch movable therebeneath into and out of the cell havingupstanding switch terminals terminated in contact members, the contactvmembers of said line and switch terminals constituting relatively fixedvertically1 aligned and spaced stationary contact members of linedisconnecting switches, and vertically movable contact members carriedby said terminal structure adapted to cooperate with and separatelybridge the pairs of aligned line and switch terminal co'ntact members,insulating means surrounding each of said movable contact members, andseparate insulating means surrounding each of said line and switchterminals arranged to cooperate with the insulating means of saidmovable contact members, whereby to enclose separately the fixed andmovable contact members of each line disconnecting switch, and operatingmeans for said movablecontact members carried by said cell struture foropening said disconnecting switches independent of and prior to theremoval of .said oil switch from the cell.

7. Electrical switching apparatus including the combination'of aterminal supporting structure, line terminals thereon having dependingcontact members, a switch disposed therebeneath having upstanding switchterminals terminated lin contact members, the contact members of saidline and switch terminals constituting relatively fixed verticallyaligned and` spaced stationary contact members of line disconnectingswitches, and vertically movable contact members carried by saidterminal structure adapted to cooperate with and separately bridge thepairs of aligned line and switch terminal contact members, an insulatingshellsurrounding said movable contact members, an insulating shellsurrounding said line terminals having a telescoping connection with theinsulating shell of said movable contact members, and an insulatingshell surrounding said switch terminals below said disconnecting contactmembers having an abutment adapted to receive the lower edge of theinsulating shell of said movable member in a lowered position thereofwhereby to enclose and isolate the several disconnecting switches. v

8. Electrical switching apparatus including the combination of anenclosing cell structure having vfixed -depending line terminals, atruck typev circuit interrupter adapted to be moved horizontally `intoand out of said cell and having upstanding switch terminals which arevertically aligned with and are spaced below said line terminals, saidconfronting line and switch terminals constituting stationary contactmembers of line disconnecting switches, a frame disposed in said cellintermediate said terminals, conducting members carried by and extendedabove and below said frame, said conducting'members constitutingthemovable switch members of said line disconnecting switches and havingupper and lower contact members adapted to cooperate with and bridge thealigned stationary contact members connecting switch members both in theraised and ,lowered positions of said frame.

9. Electrical switching apparatus including the combination of anenclosing cell structure having fixed depending line terminals, acircuitinterrupter adapted to occupy said cell -and having upstanding switchterminals which are vertically aligned with and are spaced below saidline terminals, said confronting line and switch terminals constitutingstationary contact members of line disconnecting switches, a framedisposed in said cell intermediate said terminals,v

conducting members carried by and extended above and belowsaid frame,said conducting members constituting the movable switch members of saidline disconnecting switches and having upper and lower contact membersadapted to cooperate with and bridge the aligned stationary contactmembers thereof, means to raise and lower said frame and the movableswitch members carried thereby, whereby to make and break engagementbetween said lower contact members and said switch terminals, said uppercontact members having a lost-motion electrical connection with saidline terminals, insulating means separately enclosing said alignedstationary and movable disconnecting switch members in the loweredterminal engaging position thereof, and means to displace a portion ofsaid insulating means in the Vicinity of said switch terminals in theopen position of said disconnecting switches whereby to provide anunenclosed air gap between said lower contact member and the contactmember of said switch terminal.

10. Electric switching apparatus including the combination of a mainswitch, a disconnecting switch havingI operating means thereforincluding 'a rotatable shaft adapted to be detachably engaged by a crankhandle and interlocking mechanism interconnecting said two switcheshaving means to prevent the operative engagement of said shaft by thecrank handle except when both of said switches are in predeterminedcondition.

11'. Electric switching apparatus including the combination of a mainswitch, a disconnecting switch having operating means therefor includinga rotatable shaft adapted to be detachably engaged by a crank handle andinterlocking mechanism interconnecting said two switches, and meansarranged to prevent the engagement of said shaft by the crank handleexcept when both of said switches are in predetermined con-- dition,said means including an abutment having an operative connection withsaid interlocking mechanism and movable over said shaft into and out ofa position wherein it prevents the qperative connection of the crankhandle thereto.

12. Electric switching apparatus including the combination of a mainswitch and a disconnecting switch having a frame which is verticallymovable above saidamain switch and which carries disconnect terminals,said frame having a vertical abutment member, and interlocking-mechanism interconnecting said switches arranged to prevent theoperation of said main switch except when said disconnecting switch isin fully open and fully closed positions, said interlocking mechanismincluding a member which is free to reciprocate beneath and also abovesaid abutment member when said frame is in positions lcorresponding toopen and closed positions of said disconnecting switch and is restrainedfrom movement by said abutment member when said frame is in anintermediate position whereby to lock said main switch againstoperation.

13. Electric switching apparatus including an enclosing cell having atop wall, insulating bushings, extended therethrough and terminated inthe cell in line terminals, a truck type switch located in the cellbeneath said line terminals and having upstanding terminals, and adisconnecting switch located between the line and switch terminalsarranged to connect both terminals and also to disengage the switchterminals and having a housing which encloses the line terminals whendisengaged from the switch terminals, and operating mechanismindependent of the truck switch for operating said disconnecting switch.

14. Electric switching apparatus including an enclosing cell having atop wall, insulating bushings extended therethrough and terminated inthe cell in line terminals, a truck type switch located in the cellbeneath said line terminals and having upstanding terminals, and adisconnecting switch located between said line and switch terminals andarranged to control the connection therebetween, said disconnectingswitch including a housing having contacts in the upper end which engagethe line terminals and other contacts in the lower end which engage theswitch terminals, and an insulating housing which encloses the uppercontacts and line terminals when the disconnecting switch is open andwhich surrounds and projects below the lower contacts suiciently torender difiicult manual access thereto, and operating mechanismindependent of the truck switch for operating said disconnecting switch.

15. Electric switching apparatus including an enclosing cell having atop wall, insulating bushings extended therethrough and terminated inthe cell in line terminals, a truck type switch located in the cellbeneath said line terminals and having upstanding terminals, and adisconnecting switch located between each line and switch terminal andarranged to control .the connection therebetween, said disconnectingswitches including a housing having contacts in the upper end whichengage the linev terminals and other contacts in the lower end whichengage the.

switch terminals, and an insulating housing which encloses the uppercontacts and line terminals when the disconnecting switch is open andwhich surrounds and projects below the lower contacts suciently torender difficult manual access thereto, each switch terminal having aninsulating casing which surrounds it and which is engaged by saidinsulating housing to enclose said switch terminal and lower contactwhen the disconnecting switch is closed, and operating mechanismindependent of said truck switch for operating said disconnectingswitch.

16. Electric switching apparatus comprising a cell structure having atop wall, line terminals carried by said top wall within the cell, acircuit breaker having upstanding terminals located in the cell undersaid line terminals, in combination with a disconnecting switchcomprising a frame vertically movable in said structure between saidterminals, insulated conductors carried by said frame for connecting anddisconnecting said line and breaker terminals, vertical channel memberscarried by said cell structure at opposite ends and in the median lineof said frame, said frame having guide members which are movable alongsaid channels and are arranged to guide said frame for vertical movementin parallel lines, screw-threaded shafts screw-threaded in the ends ofsaid frame at said channels for moving said frame vertically, and meansindependent of said circuit breaker for rotating both shafts conjointlyin the same effective direction.

1'7. Electric switching apparatus comprising a main switch, adisconnecting switch, actuating mechanismfor said disconnecting switchhaving a breakable operative connection therewith, and interlockingmechanism associated with both switches having means to prevent theoperative connection between said actuating mechanism and saiddisconnecting switch except when both switches are in predeterminedcondition.

18. Electrical switchgear comprising a cubicle, an oil circuit breakerunit of large interrupting capacity mounted within the' cubicle, meansfor permitting withdrawal of the unit from the cubicle, a disconnectingdevice for electrically disconnecting and isolating the circuit breakerfrom other parts of the system in which it is connected, and operatingmechanism mounted in U said cubicle independently of the circuit breakerunit for eiecting disconnection and isolation of the circuit breakerprior to withdrawal of the unit from lthe cubicle.

FREDERICK H. MACNEIL.

